﻿174 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  

  

  cisely 
  the 
  period 
  of 
  incubation 
  of 
  any 
  eggs 
  treated 
  in 
  pond-culture. 
  

   With 
  some 
  kinds, 
  under 
  extreme 
  conditions 
  of 
  temj)erature 
  and 
  other 
  

   less 
  understood 
  factors, 
  wide 
  variations 
  are 
  found. 
  Bass 
  eggs 
  require 
  

   from 
  7 
  days 
  to 
  3 
  weeks 
  for 
  hatching, 
  but 
  usually 
  from 
  8 
  to 
  10 
  days 
  — 
  

   governed 
  mostly 
  by 
  the 
  temperature 
  of 
  the 
  water. 
  Eggs 
  artificially 
  

   impregnated, 
  in 
  an 
  experimental 
  way, 
  hatch 
  in 
  from 
  70 
  hours 
  to 
  4 
  

   days 
  at 
  a 
  temperature 
  of 
  G3° 
  F., 
  or 
  somewhat 
  over. 
  

  

  When 
  the 
  fry 
  leave 
  the 
  eggs, 
  they 
  remain 
  on 
  the 
  nest 
  till 
  the 
  sac 
  is 
  

   absorbed, 
  this 
  depending, 
  as 
  with 
  other 
  fishes, 
  on 
  the 
  period 
  of 
  incu- 
  

   bation, 
  modified 
  by 
  the 
  temperature 
  or 
  condition 
  of 
  the 
  atmosphere; 
  

   usually 
  a 
  fifth 
  less 
  time 
  being 
  required 
  to 
  absorb 
  the 
  sac 
  than 
  for 
  hatch- 
  

   ing 
  the 
  eggs. 
  When 
  the 
  sac 
  is 
  absorbed, 
  the 
  fry 
  rise 
  from 
  the 
  nest 
  

   and 
  form 
  a 
  school 
  which 
  hovers 
  over 
  the 
  nest 
  usually 
  from 
  two 
  to 
  four 
  

   days, 
  settling 
  back 
  at 
  night, 
  except 
  in 
  extremely 
  warm 
  weather, 
  when 
  

   they 
  may 
  scatter 
  in 
  a 
  few 
  hours. 
  A 
  sudden 
  fall 
  of 
  temperature 
  may 
  

   cause 
  the 
  school 
  to 
  settle 
  back 
  and 
  remain 
  a 
  day 
  or 
  two 
  longer 
  on 
  the 
  

   nest. 
  The 
  tactics 
  of 
  the 
  parents 
  change 
  and 
  they 
  no 
  longer 
  stand 
  

   guard 
  over 
  the 
  nest, 
  but 
  circle 
  around 
  the 
  school, 
  whipping 
  back 
  truants 
  

   and 
  driving 
  off 
  intruders. 
  When 
  the 
  school 
  rises 
  and 
  hunger 
  begins 
  

   to 
  be 
  felt, 
  the 
  fry 
  separate 
  and 
  are 
  driven, 
  for 
  j)rotection, 
  by 
  the 
  parent 
  

   fish 
  into 
  vshoal 
  water 
  or 
  into 
  the 
  thick 
  grasses; 
  there 
  they 
  are 
  deserted, 
  

   and 
  dispersing, 
  they 
  seek 
  the 
  minute 
  Crustacea, 
  larvte, 
  and 
  insects. 
  

  

  Black-bass 
  fry 
  do 
  not 
  average 
  one-fourth 
  of 
  an 
  inch 
  in 
  length 
  and 
  

   are 
  almost 
  colorless 
  for 
  the 
  first 
  three 
  to 
  five 
  days, 
  when 
  the 
  pigment 
  

   forms 
  along 
  the 
  back, 
  making 
  them 
  appear 
  quite 
  dark 
  when 
  viewed 
  

   from 
  above, 
  though 
  it 
  is 
  difficult 
  to 
  distinguish 
  the 
  color 
  of 
  an 
  indi- 
  

   vidual 
  fish 
  when 
  caught 
  on 
  a 
  net 
  of 
  bolting-cloth. 
  

  

  Very 
  young 
  rock 
  bass 
  seem 
  occasionally 
  to 
  attach 
  themselves 
  to 
  the 
  

   sides 
  and 
  bottom 
  of 
  the 
  nests 
  and 
  to 
  submerged 
  plants. 
  This 
  action 
  

   has 
  not 
  been 
  noticed 
  with 
  black 
  bass, 
  possibly 
  because 
  their 
  nests, 
  

   being 
  in 
  deeper 
  water, 
  are 
  more 
  difficult 
  of 
  observation. 
  

  

  FOOD 
  OF 
  THE 
  YOUNG. 
  

  

  Just 
  how 
  much 
  food 
  to 
  give 
  the 
  young 
  bass 
  fry 
  is 
  as 
  difficult 
  to 
  

   determine 
  as 
  with 
  any 
  other 
  young 
  fish. 
  They 
  are 
  very 
  greedy, 
  and, 
  if 
  

   acceptable 
  food 
  is 
  given 
  them, 
  appear 
  to 
  be 
  hungry 
  nearly 
  all 
  the 
  time, 
  

   and 
  it 
  is 
  more 
  than 
  probable 
  that 
  the 
  troubles 
  caused 
  by 
  overfeeding 
  

   other 
  fishes 
  would 
  show 
  themselves 
  in 
  the 
  bass 
  if 
  they 
  were 
  overfed. 
  

   Bass, 
  like 
  the 
  trout, 
  are 
  given 
  about 
  li 
  per 
  cent 
  of 
  their 
  weight 
  in 
  food 
  

   per 
  day. 
  This 
  ratio 
  will 
  maintain 
  black-bass 
  fry 
  in 
  a 
  healthy 
  growing 
  

   state, 
  and 
  probably 
  less 
  will 
  be 
  found 
  to 
  answer 
  with 
  rock-bass 
  fry. 
  

   Comi)ared 
  with 
  other 
  fishes 
  reared 
  in 
  troughs, 
  especially 
  some 
  of 
  the 
  

   trout, 
  bass 
  are 
  easily 
  managed. 
  Healthy 
  fry 
  have 
  been 
  carried 
  at 
  

   Neosho 
  for 
  four 
  months 
  with 
  a 
  loss 
  of 
  only 
  2 
  per 
  cent. 
  When 
  first 
  

   brought 
  into 
  the 
  troughs, 
  they 
  can 
  not 
  be 
  induced 
  to 
  take 
  the 
  prepared 
  

   food, 
  as 
  they 
  are 
  wild 
  and 
  must 
  be 
  tamed 
  or 
  domesticated. 
  They 
  are 
  

  

  